To build either type of fusion cube the Borg had first to have built a fusion hub within the local area of space they were operating. Once the hub was developed the Collective could then select eight cubes which would place themselves in a careful formation and fuse.

Tactical fusion cubes had a crew of thousands, were heavily armed and had powerful shields, making them one of the most powerful vessels in the Borg fleet. A tactical fusion cube could effortlessly repel attacks from even the most formidable opponents - easily outgunning and overpowering even a starbase.

Tactical fusion cubes do not appear as computer controlled units in any of the missions in Armada II - as the AI is incapable of creating either type of fusion cube the only way one could appear was if it were placed as given map unit for the computer player, which does not occur in any of the missions. Further they can only be built by a human player in the final mission, where, as the most powerful vessel in the game, they can be very useful as one of the ways to destroy the Species 8472rift maker; a massive and very powerful unit that must be destroyed to complete the game.

Players playing as the Borg could make tactical fusion cubes in "instant action" games.

Using the technology assimilator tactical fusion cubes could assimilate up to four "special weapons".